Method for continuously making pearlescent plastic sheeting



June 30, 1970 G. R. ADEY ET AL 3,518,333

METHOD FOR CONTINUOUSLY MAKING PEARLESCENT PLASTIC SHEETING Filed May15, 1967 5 Sheets-Sheet l FIG.

74 log //4 5 FIG. 2 20 l 238 L94 Z/Z INVENTORS. GEORGE R. ADEY W/LMERSOUDER, R.

arM/i A TTORNEYS.

J1me 1970 G. R. ADEY ET AL METHOD FOR CONTINUOUSLY MAKING PEARLESCENTPLASTIC SHEETING 5 Sheets-Sheet Filed May 15, 1967 WED lNl/ENTORS.GEORGE R. ADE) June 30, 1970 G. R. ADEY ET AL 3,518,333

METHOD FOR CONTINUOUSLY MAKING PEARLESCENT PLASTIC SHEETING Filed May15, 1967 5 Sheets-Sheet 4 FIG/0 "ll'ia i1: is 272 El -1 rays: 2!?! caqzaqua age: :gz sq:

274 I 278 ll. 82 286 226 u n a a 22 303 3/0 3/4 3/8 328 322 //vvz/vroms.

GEORGE R. ADE'Y F /2 W/L MER SOUDER, J?

A TTORNEVS.

June 30, 1970 ADEY ET AL SHEETING METHOD FOR CONTINUOUSLY MAKINGPEARLESCENT PLASTIC Filed May 15, 1967 5 Sheets-Sheet 5 INVENTORS.GEORGE R. A 05) W/LMER $OUDR,J/?.

B y k United States Patent 3,518,333 METHOD FOR CONTINUOUSLY MAKINGPEARLESCENT PLASTIC SHEETING George R. Adey, Huntingtlon Valley, andWilmer Souder,

Jr., Pottstown, Pa., assignors to Denton Plastic Products Corp.Southampton, Pa., a corporation of Maryland Filed May 15, 1967, Ser. No.638,482 Int. Cl. B29b /00; B2d 7/02 US. Cl. 26470 1 Claim ABSTRACT OFTHE DISCLOSURE This invention relates to a method for continuouslymaking pearlescent plastic sheeting. More particularly, this inventionrelates to a method for continuously making an'orien ted pearlescentplastic sheeting having one or more colors.

At the present time plasticarticles exhibiting a pearlescent effect orsheen are manufactured in a variety of ways. Pat. 2,856,635, by way ofexample, discloses a method and apparatus which is capable ofmanufacturing only a single sheet of plastic material during eachoperation of the machine. To the same effect are the methods describedin Pats. 2,265,266, 2,480,749, and recently, Pat. 3,046,610. Plasticarticles produced as described therein, having a pearlescent sheen havemany uses, such as for buttons, wall plaques, jewelry and the like.

Such processes are however batch-type methods of manufacturing. Thedisadvantages of any batch-type operation are manifest. They areinherently slow and inefiicient if for no other reason than because theyinvolve machine down time just to remove the completed plastic product.Moreover, there is the additional time factor in preparing the machinefor the next batch of plastic resin. Thus, the machine surfaces must becleaned, a pre-measured batch of resin pigmented with pearlescence mustbe prepared, and where applicable, time must be allowed for mixing toincorporate a catalyst uniformly into the batch, and then the batch mustbe applied to the machine.

The present invention overcomes the foregoing disadvantages byincorporating them into a continuous process and providing an apparatusfor effecting such a process. For example there are known methods andapparatus for continuously catalyzing many thermosetting resins,however, such methods and apparatus have never been used for thecontinuous production of plastic sheeting having oriented pearlescenceand therefore a pearlescent sheen. Moreover, such methods and apparatusas are known produce undesirable effects in the final product. Thus, itis a general object of the present invention to provide a continuousmethod for preparing plastic sheeting having oriented pearlescence andthereby articles having a pearlescent sheen.

It is another object of the present invention to provide a method forcontinuously making pigmented thermoplastic or thermosetting plasticsheeting having an oriented pearlescent sheen.

Other objects will appear hereinafter.

For the purpose of illustrating the invention, there is shown in thedrawings a form Which is presently preferred; it being understood,however, that this invention is not limited to the precise arrangementsand instrumentalities shown.

FIG. 1 is a sid view of apparatus for manufacturing plastic sheetinghaving a pearlescent effect in accordance with the present invention.

FIG. 2 is an end view of the apparatus shown in FIG. 1 taken along theline 22.

FIG. 3 is a top view of the apparatus illustrated in FIG. 1 taken alongthe line 3-3.

FIG. 4 is a sectional view of the apparatus illustrated in FIG. 1 takenalong the line 44.

FIG. 5 is a partial transverse sectional view of the apparatusillustrated in FIG. 1 taken along the line 55.

FIG. 6 is a partial sectional view of the apparatus illustrated in FIG.2 taken along the line 6-6.

FIG. 7 is an enlarged partial sectional view of a mixer nozzle.

FIG. 8 is a partial sectional view of a reciprocating drive apparatustaken along the line 88 in FIG. 4.

FIG. 9 is a partial sectional view of a clamping means taken along theline 99 in FIG. 3.

FIG. 10 is a side view of the mixing and pumping apparatus taken alongthe line 1010 in FIG. 2.

FIG. 11 is a partial top view of the apparatus illustrated in FIG. 10taken along the line 1111.

FIG. 12 is a schematic illustration of a second embodiment of thepresent invention.

FIG. 13 is an exploded view of a third embodiment of the presentinvention.

Referring now to the drawings in detail, there is shown in FIG. 1 anapparatus for continuously making plastic sheets of resin having apearlescent effect, designated generally as 10. As best shown in FIG. 2,the apparatus 10 includes two basic components, namely a receiving andorienting section designated generally as 12 and a catalyzing andfeeding section designated generally as 1 4. The sections 12 and 14 aredescribed separately, and then they are combined in connection with thedescription of their operation.

Referring now to FIGS. 1, 2, 3 and 4, the receiving and orientingsection 12 comprises a stand 16 which includes two pairs of end legs 18;18 and 20; 20 which together with intermediate legs 22 and 24 supportside rails 26 and 28 which extend between the legs 18 and 20, andbetween the legs 18 and 20, respectively. End rails 30 and 32 extendbetween the side rails 26 and 28 and are joined to them. In thepreferred embodiment, the foregoing described members of stand 16 aremanufactured from channel steel and welded at the joints. While thestand 16 may be made with other materials and from members which areshaped differently, it is important that the stand be constructed so asto provide a rigid supporting structure.

The stand 16 supports a rigid frame 34 that is preferably made fromwelded tubular members. As shown, the frame 34 includes a pair of spacedapart side members 36 and 38 which are joined together by a pair ofreinforcing cross members 40 and 42. Cross members 40 and 42 arepreferably joined to side members 36 and 38 by weldments. Bearings 44,46, 48 and 50 are fixed to the ends of side members 36 and 38 by meansof a threaded rod and nut assembly designated generally as 52. A hearingarm 54 extends through the bearings 44 and 46 and through slottedopenings 58 and 60 into bearing housings 62 and 64. Similarly, a bearingarm 56 extends through bearing 48 and 50 and through slotted openingsinto bearing housings 66 and 68. As thus described, the frame 34 ishorizontally mounted on stand 16 for reciprocable movement in ahorizontal plane. The apparatus for reciprocating the frame 34 isdescribed hereinafter.

Support rails 70 and 72 extend along and are fixed to the side members36 and 3 8 of frame 34. As best shown in FIG. 5, the support rails 70and 72 consist of angle members open to the outer side of the sidemembers 36 and 28 with their laterally projecting flanges extendingoutwardly. As described more clearly below, the support rails 70 and 72provide a base upon which an endless chain conveyor moves.

Sprockets 74 and 76 are mounted on the bearing arm 54 adjacent thebushings 44 and 46. In a like manner, sprockets 78 and 80 are mounted onthe bearing arm 56 adjacent the bushings 48 and 50. A shaft 82 isjournaled in bearings 84 and 86 intermediate the top and bottom of legs18 and 1 8'. The second shaft 88 is journaled in bearings 90 and 92intermediate the top and bottom of legs 20 and 20. Sprockets 94 and 96are fixed on the shaft 82 at a position immediately below the sprockets74 and 76. Sprockets 98 and 100 are fixed on shaft 88 immediately belowthe sprockets 78 and 80. The above described sprockets support endlesschain belts 102 and 104 for a continuous movement along the supportrails 70 and 72 in the manner of a conveyor. As shown, endless chainbelt 102 extends along support rail 70, engages sprocket 78, descendsdownwardly and engages sprocket 98, is engaged by a sprocket 136 on thedrive mechanism, engages sprocket 94, and then extends upwardly intoengagement with sprocket 74. Similarly, endless chain belt 104 engagessprocket 80, descends downwardly and engages sprocket 100, extends thelength of the apparatus below the frame 34 and is in engagement with adrive sprocket 104, engages the sprocket 96 and extends upwardly intoengagement with sprocket 76. As thus mounted, the endless chain belts102 and 104 can be driven continuously over the support rails 70 and 72.

A second stand 106 is positioned beneath the stand 16 and provides aplatform for the endless chain belt drive and for the frame 34reciprocating apparatus. The reciprocating apparatus comprises anelectric motor 108 mounted on stand 106. Motor 108 drives a pulley 110about which extends a belt 112. The belt 112 extends about a secondpulley 114 which is fixed on shaft 116. Shaft 116 is journaled inbearings 118 and 120 which are mounted above the stand 106. As shown inFIG. '8, an eccentric bearing 122 is fixed to shaft 116 and thereforerotates with it. Bearing 122 is fixer to rod 126 which is connected torod arms 128 and 130 which in turn are connected to bearing arm 56 onframe 34 by means of the bushings 132 and 134.

As thus assembled, the reciprocating motion developed in rod 126 by thebearing 122 Will be transmitted to the frame 34 which will reciprocatewithin the bearing housings 62, 64, 66 and 68. The diameter of pulley114 is adjusted in relation to the speed of motor 108 and the diameterof pulley 110 to provide the required rate of reciprocation.

The drive apparatus for endless chain belts 102 and 104 is mounted onstand 106 and includes sprockets 136 and 138 which are fixed to shaft140. Shaft 140 is journaled in bearings 142 and 144 which are mounted onstand 106. A one way clutch 146 is also mounted on shaft 140. Aconnecting arm 148 extends from clutch 146 and is rotatably connected topiston rod 150. Piston rod 150 is, in turn, connected to a piston withinhydraulic cylinder '2. Cylinder 152 is rotatably journaled in bearing154.

Clutch 146 is a conventional one Way type of clutch mounted so thatcounterclockwise rotation of connecting arm 148 by application ofhydraulic pressure to piston rod 150 through cylinder 152 will causeshaft 140 to rotate counterclockwise as viewed in FIG. 1. Whenconnecting arm 148 and piston rod 150 return to their normal position asshown in FIG. 1, clutch 146- releases from shaft 140 and thus does notrotate it. The clockwise rotation of shaft 140 is transmitted tosprockets 136 and 13-8 which in turn drive endless chain belts 102 and104 in a clockwise direction as viewed in FIG. 1.

The primary braking system for holding the endless chain belts 102 and104 in position except during the forward stroke of piston rod 150-comprises a disc 164 fixed on shaft 88 between a pneumatically operatedclamp 166. The clamp 166 is connected to a source of gas pressure (notshown) and to an electrical control mechanism (not shown) which causesit to engage the disc 164 while the piston rod 152 is in its normalposition and to release the disc 164 during the forward and returnstroke of the piston rod 150.

To assist in preventing endless chain belts 102 and 104 from slipping ineither a clockwise or counterclockwise direction during the brief periodwhen cylinder 152 is returning rod and connecting arm 148 to thestarting. position, an auxiliary brake mechanism has been provided. Theauxiliary bra ke mechanism consists of a pulley 156 fixed on the end ofshaft 140. A bracket 158 is fixed to and extends from stand 106. A belt160 is wound about pulley 156 and has one end fixed to bracket 158. Theother end of belt 160 is fixed to a spring 162 which in turn is fixed tobracket 158. Belt 160 is preferably cylindrical and in moderatefrictional engagement with pulley 156. The amount of frictionalengagement can be adjusted by expanding or contracting spring 162. Thefrictional force between pulley 156 and belt 160 is sufiicient toprevent the endles chain belts 102 and 104 from moving during the periodwhen connecting arm 148 and piston rod 150 are returning to theirstarting position. However, the frictional force is sufficiently smallso that the force of cylinder 152 on its forward stroke will overcome itand cause the belt 160 to slip on pulley 156.

Pneumatic pressure for cylinder 152 is supplied from a source of gaspressure (not shown) and is controlled in itsapplication to the cylinderby apparatus to be described hereinafter.

The apparatus is provided with means by which trays 172 can bepositioned at the entrance end and removed at the exit end of the movingendless chain belts. As best shown in FIGS. 1 and 3, a plurality ofspring biased retaining clamps 168 are mounted at spaced intervals onthe endless chain belts 102 and 104. In addition, a plurality of fixedblocks 170 are positioned on endless chain belts 102 and 104 at spacedintervals from the clamps 168. The clamps 168 and blocks 170 cooperateto retain a liquid supporting surface in the form of a tray on theendless chain belts 102 and 104 as they traverse the distance across thetop of stand 16. Referring to FIG. 9, there is shown an enlarged view ofa clamp 168 on endless conveyor chain 102. The clamp 168 includes a base174 which is welded or otherwise fixed to the endless chain belt 102. Aback member 176 is fixed to the base 174 and provided with a recess 178for the spring 180. A gripping member 182 is slidably mounted on base174 by means of a tenon and groove. A recess 184 is provided in grippingmember 182 for receiving spring which tends to bias it forward against ablock fixed to base 174. Gripping member 182 is also provided with aflange 186 that projects outwardly and over the tray 172. The biasingforce from spring 180 on clamp 186 forces the tray 172 against acooperating block 170 spaced from the clamp 168 by a distance slightlyless than the length of the tray. The clamping force between grippingmember 182 and the block 170, together with the retaining function offlange 186, is sufiicient to hold the trays 172 in position during thecombined reciprocating and intermittent displacement of the endlesschain belts 102 and 104. The sets of clamps 168 and blocks 170 can bepositioned on the endless chain belts 102 and 104 so that there is onlya small open space between trays 172 as they move along the stand 16.

The trays 172 provide a means for receiving liquid plastic resins in amanner to be described hereinafter. Preferably the trays are providedwith small side rails for preventing the resin from spilling over duringthe initial application. However, if the trays are wide enough suchrails may not be necessary. More importantly, the trays provide asurface upon which the liquid may be received and a means by which thereciprocating motion of frame 34 can be transferred to the liquid resinto impart orientation in one plane to the pearlescence. The surface ofthe tray can be smooth to give orientation in a single plane, orpatterned to give the orientation a rippling or wavy effect.

The means for distributing liquid resin on the trays 172 include a frame188 comprising a cross bar 189 supported over the stand 116 by a pair ofuprights 190 and 192. A sprocket 194 is fixed to the shaft of motor 196which is mounted on the cross arm 189. A second sprocket 198 isrotatably mounted on bracket 200. An endless chain 202 extends aroundthe sprockets 194 and 198 and has fixed thereon a sliding block 204.Block 204 is slidably mounted in a slot 206 in nozzle support plate 208.Support plate 208 is slidably mounted on guide rods 210 and 212.

As thus constructed, energization of electric motor 196 drives endlesschain 202 about the sprcokets 194 and 198. Block 204 will move with thechain about the sprockets, and at the same time it will move up and downin slot 206. In this manner, the plate 208 is caused to reciprocatetransversely across the stand 16. The distance between sprockets 194 and198 fixes the length of traverse of plate 208. If desired this distancecan be adjusted by providing adjustable mounts for electric motor 196and sprocket 198.

Microswitches 214 and 216 are adjustably mounted on guide rod 210 atpositions adjacent the sprockets 194 and 198. Microswitches 214 and 216are positioned so that the plate 208 will engage and close them at theend of each traversal of the receiving and orientating section 12.Microswitches 214 and 216 are connected to an electrical control circuitwhich is operative to open and close solenoid valves in the hydrauliclines between cylinder 152 and the aforesaid reservoir of hydraulicfluid and between the hydraulic clamp 166 and said reservoir. The effectof the control circuit is to energize cylinder 152 and thereby drive theendless chains 102 and 104 forward a predetermined distance. At the sametime, the hydraulic clamp 166 on disc 164 is released. The controlcircuit includes timing means for holding the clamp 166 in open positionuntil cylinder 152 has driven piston rod 150 completely forward. Thecontrol circuit is conventional and therefore need not be described indetail.

Plate 208 supports one to four nozzles such as nozzles 218, 220, 222 and224 in vertical alignment above the tray 172. The nozzles 218224 extendequal distances outwardly from plate 208. As thus mounted andpositioned, each nozzle 218-224 will discharge liquid resin at the samearea on the surface of trays 172.

Referring to FIG. 7, an enlarged view of nozzle 218 is shown. As thisnozzle is identical with nozzles 220, 222 and 224, it will be describedas being representative thereof. A pair of hoses 226 and 228 areconnected to the inlet side of the nozzle 218. As will be explainedhereinafter, the hoses 26 and 228 conduct resin from different sourcesto the nozzle. Each nozzle is provided with a means to intimately mixthe fluids flowing from hoses 226 and 228. By way of example there ispositioned within each nozzle a mixer 230 in the form of a flat helicalmember extending throughout the length of the nozzle. The mixer 230causes intimate mixing of the liquid resins fed by hoses 226 and 228. Ifdesired, a Bink mixer could be substituted.

Referring now to FIGS. 2, and 11, there is shown in detail, thecatalyzing and feeding apparatus 14. Apparatus 14 includes a stand 232upon which is supported an intermediate stand 234. Mounted on theintermediate stand 234 are containers 236 and 238. Each of thecontainers 236 and 238 is provided with a bracket upon which is mountedan electric mixer 240 for stirring the liquid resins within thecontainers. Mounted directly on the stand 232 and below the containers236 and 238 are four additional containers 242, 244, 246 and 248. Aliquid conduit 250 is connected to an opening in the bottom of container238 and is provided with outlets which open directly into containers242, 244, 246 and 248. A valve 252 may be provided between container 238and conduit 250 to control the rate of flow through it.

A platform 254 is mounted on the stand 232 below the containers 242248.Four pump motors 256, 258, 260 and 262 are supported on platform 254.The output shaft of each pump motor 256462 is provided with sprockets264, 266, 268 and 270, each of which engage and drive two gear pumps272, 274; 276, 278; 280, 282; and 284, 286, also mounted on platform254. It should be understood that other types of pumping means could beused. However, the advantage of gear pumps is that the rate of pumpingcan be adjusted simply by changing the speed of the drive shafts ofmotors 256262. As will be explained hereinafter, it is expected that inthe operation of the apparatus, each motor-pump set, consisting of thedrive motor and two pumps, will be operated at different pumping rates.

As illustrated in FIG. 10, the container 236 opens into a conduit 288which in turn branches out into four additional conduits illustratedschematically in FIG. 10 as 290, 292, 294 and 296. Each of the conduitbranches 290- 296 is connected to a gear pump as best illustrated inFIG. 11. A valve 298 is mounted in conduit 288 for providing additionalflow control.

Conduits 300, 302, 304 and 306 provide communication between thecontainers 242-248 and individual gear pumps 274, 278, 282 and 286,respectively. If desired, valve means (not shown) can be mounted inconduits 300306 to provide additional flow control for liquids.

As thus assembled, each of the motor-pump sets is delivering two sourcesof liquid, one of which is fed directly from container 236 and thesecond of which is fed from container 238 through containers 242248.Each pair of outlet conduits, such as conduits 226 and 228, is connecteddirectly from the gear pumps to one of the nozzles 218-224. Thus,conduits 308 and 310 are connected to nozzle 220, conduits 312 and 314are connected to nozzle 222 and conduits 316 and 318 are connected tonozzle 224.

Having described in detail the apparatus shown in FIGS. 1-11, itsoperation will be described in connection with the manufacture ofplastic sheets having a pearlescent effect. The operation describedhereinafter, will be preferably directed to the use of a thermosettingresin. However, it will be readily apparent to one skilled in the artthat the process described is equally suited to be used with materialsother than thermosetting resins. For example, a wide variety of resinswhich can be characterized as thermoplastic may also be employed.Modifications to the structure described may be required when usingmaterials other than thermosetting resins. Such modifications, however,are well within the skill of workers in the art. Extensiveexperimentation will not be required for adaptation to the classes ofmaterials disclosed herein.

Polyester resins are the preferred thermosetting resins for use in theapparatus of this invention. The most suitable polyester resin can beselected from the products of unsaturated dibasic acids with unsaturatedglycols. Unsaturated dibasic anhydrides may also be used, such as maleicanhydride. The preferred unsaturated glycols suitable for use in thepractice of the present invention would include propylene glycol,diethylene glycol and the like. It is further preferred that thepolyester resins used in the process and operation of the apparatus ofthis invention be modified with the addition of predetermined quantitiesof certain monomers. Very desirable properties are obtained frompolyester resins containing modifying monomers such as styrene, acrylicmonomers such as methyl rnethacrylate, allyl monomers such as diallylphthalate, vinyl monomers, and mixtures and copolymers thereof. It isfurther well known in the art of preparing unsaturated polyesterpolymers that mixtures of unsaturated dibasic acids or anhydrides andmixtures of alcohols will modify the properties of the resultant polymerin a known manner. Conventional commercial preparations of thesematerials are well adapted for use in the process and apparatus of thepresent invention.

Other thermosetting resins suitable for use herein would includepolyethers such as epoxy resins.

Thermoplastic materials may also be used in the method and apparatus ofthe present invention. Specific polymers which would be suitable forsuch use would include polymers or copolymers of materials containing anethylenic linkage. Examples of monomers suitable for preparation ofpolymeric materials useful in this invention are acrylic monomers andstyrene and substituted styrene monomers.

It is also possible to use resin-containing solvent systems andplastisols and plastigels containing suitable clear-curing resins, toprepare oriented pearlescent sheeting as disclosed herein. Suchmaterials would require providing the apparatus disclosed herein with ameans for controlling the rate of solvent evaporation during theformation of the sheeting. Proper control of the evaporation wouldpermit the resin to set to a non-flowable state after the pearlescencehas been oriented according to this invention. The specific apparatusfor accomplishing the desired control over the rate of evaporation hasnot been illustrated. Such devices are well known in the art of castingsheets or films of resins or polymers from solvent systems, and couldemploy means for applying heat such as by hot air or the like orevaporation under reduced pressure by passing the sheet through asolvent-stripping low pressure environment.

In a similar manner modifications to the apparatus disclosed which maybe necessitated by the use of thermoplastic material are well within theskill of a worker in this art. For example, the thermoplastic resins maybe emloyed to form self-supporting sheeting by applying thethermoplastic material to the trays 172 in a fluid condition. In thecase of some resins, this would necessitate using heaters, possibly onthe storage tanks and the supply hoses. Likewise, an appropriatedistance downstream from the application of such material, a coolingmeans could be provided to set the thermoplastic resin into anonflowable state once the pearlescence has been oriented within thesheeting according to this invention.

Typically, during the operation of the apparatus described herein, thedesired amount of a polyester thermosetting resin to be used in apredetermined time period of machine operation is formulated and dividedin half. One half is placed in container 236 and the other half isplaced in container 238. A catalyst is added into the container 236 andthoroughly mixed by the mixer 240. In a like manner, if desired, a waxcan be added to form a protective air barrier so that the exposedsurface of the resin will set without being affected by the air. Theapplication of wax in this manner provides the thermosetting resin witha non-tacky surface. Such a condition will be referred to hereinafter asa surface which has dried to the touch.

A promoter is added to the resin in container 238 and thoroughly stirredby the mixer 240.

Pearlescence is added to the containers 242-248. Thus, the containers242-248 may contain white pearlescence, or other coloring materials,including colored pearlescence having both reflected and transmittedcolors:

To begin the operation, the receiving and orientating section 12 isplaced into operation by energizing motors 108 and 196 as well as theelectrical control for hydraulic cylinder 152 and hydraulic clamp 166.Thus, the frame 34 begins to reciprocate on stand 16 at a rate which inthe preferred embodiment is approximately 250-500 cycles per second overa distance of approximately plus or minus /2 to 1 inch. At the sametime, the nozzles 218-224 are traversed back and forth across the trays172. The rate of traversal is adjusted to provide the preferredthickness. At the end of each traversal, the hydraulic cylinder 152 isactuated and biases the endless conveyor belts 102 and 104 forwardapproximately l-2 inches. The rate of traversal and the amount ofmovement forward at the end of each traversal depends upon the type ofresin being used and the rate at which it is expected to gel.Accordingly, the numbers set forth above should be regarded as exemplaryand in no way limiting.

By opening valve 298, resin flows from containers 236 to the motor-pumpsets. As explained hereinbefore, resin flows directly from container 236to pumps 272, 276, 280 and 284. When valve 252 is opened, resin andpromoter from container 238 flows into containers 242, 244, 246 and 248.Then it is mixed in these containers with the desired pearlescence andappropriate pigment. From containers 242-248 it flows to pumps 274, 278,282 and 286. Once containers 242-248 have been filled with sufiicientresin for a specified run the valve 252 is closed. Thereafter, thecontainers 242-248 are the sole source of resin mixed with pearlescence.

During all of the mixing and pumping operations care must be taken toavoid the formation of air bubbles.

The rate of feed from individual pumps to the nozzles 218-224 isdetermined by the speed of the individual motors 256-262. Thus, if thefinal product is to have more from one container than another, thenpumps 276 and 278 could operate at a greater rate than pumps 280 and282.

All pumps are started and the resin containing catalyst mixture and theresin containing promoter and pigment reach the nozzles 218-224, theyare thoroughly intermixed by mixer 230 to thereby chemically actuatethem, and then expelled directly onto the surface of trays 172. Sincethe nozzles are vertically aligned, each nozzle will drop its materialonto the same area of the tray, depending upon the position of thenozzle plate 208.

It is ordinarily possible to use only one nozzle. But to increase flowrate two, three or four can be used. Also, the additional nozzles allowfor the use of color or colored pearlescence, or for continuous use whena first nozzle becomes inoperative.

The overall effect of the intermittent displacement of the traystogether with the traversing movement of the nozzles is to lay down anundulating stream of resin on the surface of the trays. The effect ofthe reciprocating motion imparted to the trays is twofold. The first,and most important, is that it orientates the pearlescence in parallelhorizontal planes. The second effect is that it causes the undulatingstream to merge so as to form a sheet of uniform thickness.

The side walls of the trays 172 prevent the plastic material fromflowing off before it sets into a non-flowable mass.

The rate of movement of the trays away from the area of impingement ofthe plastic material depends upon the setting rate of the plastic. Ingeneral, the length of the conveyor or the rate at which it moves is tobe adjusted so that the chemical reaction to set the plastic materialhas continued to a point where upon being removed from the trays whenthey reach the end of the stand 16, the sheet is ready to be removed forfurther operations such as blanking. Thus, between the area ofimpingement and a point along the trays 172 where the plastic has set toa non-flowable state, hereinafter referred to as the gel point of theresin, the apparatus 10 has converted the resin containing unorientedpearl essence into semi-solid oriented pearlescent sheeting. Moreover,this process is continuing at a constant rate because catalyzed resin isbeing continuously flowed onto the trays.

While the present invention has been described in one form, it should beunderstood that other forms are possible. For example, rather thandividing the desired amount of resin in half and adding catalyst to onehalf and promoter to the other half, the following alternative could beused. The promoter is added to the entire amount of resin and thecatalyst is introduced undiluted through its own pumps or pumps justprior to the mixing nozzle or nozzles. Likewise where only a narrowsheet is desired the nozzles do not have to be traversed across thetrays. Moreover, a conveyor belt can be substituted for the trays andthe endless chain belts 102 and 104 can be driven at a constant rate.

Referring now to FIG. 12, a schematic illustration of another type ofcontinuous apparatus is shown. The apparatus is designated generally as320 and only those portions of the apparatus which differ from theapparatus are illustrated. As shown, the apparatus 320 includes a lowerconveyor belt 322 and an upper conveyor belt 324, each driven in thedirection indicated by the semicircular arrows. In addition, both belts322 and 324 are reciprocated by means such as described with relation tothe apparatus 10. The belts 322 and 324 are reciprocated at the samerate and preferably from a common drive. Preferably, the belts 322 and324 are dammed at the sides to prevent liquid resin from overflowing. Asshown, belt 324 is shorter than belt 322 to provide a receiving area forresin from nozzles 326 and 328 supported thereabove. Conveyor 324 ispositioned relatively close to conveyor 322 so that it contacts resindeposited on conveyor 322. The advantage of such an apparatus is that itpromotes orientation of the pearlescence from both the top and bottomsurface of the finished plastic sheeting.

The conveyor belts, such as belt 322, are preferably made of metal, andcan be continuous strips, or continuous strips which are sectioned off.

Referring now to FIG. 13, there is shown a perspective view of anotherembodiment of the present invention. In this embodiment means are shownwhereby the basic structure of the receiving and orientating section 12can be modified by adding to it a continuous belt for producingcontinuous sheets of plastic.

To simplify the description, the supporting frame structure for thereceiving and orientating section has been omitted from FIG. 13. Allstructure herein shown has been assigned the same number that it had inthe other figures of the drawings. Thus, like numerals indicate likeelements as described with respect to FIGS. 1-11.

A continuous belt apparatus which is adapted to be fitted onto thereciprocable frame 34 is designated generally as 400. Belt apparatus 400comprises a pair of elongated channel members 402 and 404 which aresubstantially longer than the distance between the bearing arms 54 and56. Thus, the overall length of the continuous belt apparatus 400 isgreater than that of the receiving and orientating section 12.

The channel members 402 and 404 are held in opposed parallelrelationship by a plurality of reinforced cross members 406 which extendbetween them and join them together. Mounted adjacent either end of thechannel members 402 and 404 are drums 408 and 410. Drums 408 and 410 aremounted on axles 412 and 414 which extend through bearings 416 and 418mounted to the bottom members 402 and 404.

Bearings 416 and 418 are preferably mounted so as to be adjustable inthe longitudinal direction. Thus, threaded members such as members 420,422 and 424 extend through internally threaded blocks, such as blocks426 and 428, and are rotatably connected to bearings 416 and 418. Thebearings 4.16 and 418 are slidably mounted on channel members 402 and404 so as to be adjustable in the longitudinal direction. By rotatingthe threaded members 420-424, the bearings 416 and 418 can be movedtoward and away from each other thereby providing a means to adjust thetension in the belt 430 which extends around the drums 408 and 410.

Belt 430 is preferably made of a flexible metal, such as stainlesssteel. The belt extends around the drums 408 and 410 and over therollers 432 and 434 which bias the lower portion of the belt upwardly toavoid interference with the frame 34 and the operating apparatus of thereceiving and orientating section 12.

The length of the channel members 402 and 404 is suflicient to allow thedrums 408 and 410 to be spaced apart far enough so that they are beyondthe bearing arms 54 and 56 and thus do not interfere with them.

The belt 430 is normally held under suificient tension by the adjustmentmeans described above so that no support means is required. However,panels 436 and 438 could be provided if desired.

Thus described, the belt apparatus 400 is adapted to be carried by someform of lifting apparatus, such as a fork lift, and positioned on theframe 34. To retain the belt apparatus 400, a plurality of clamps, suchas clamps 440 and 442 have been provided. These clamps fit over the sidemembers 36 and engage the same to retain the belt apparatus 400 in placethereon.

The means for reciprocating the frame 34 is the same as that describedabove. However, it is no longer necessary to operate the apparatus forindexing the chain belts 102 and 104, since a separate drive is providedfor the belt 430.

As shown, the drive for belt 430 includes a sprocket 444 mounted on theend of shaft 414. A drive belt 446 extends around the sprocket 444 andengages a sprocket 448 on shaft 450. Shaft 450 is mechanically connectedto a gear box 452 which in turn is mechanically connected to a motor454. Gear box 452 provides a means for adjusting the speed of the belt430. Those skilled in the art will readily recognize that other gearingand/or velocity adjusting means may be provided.

Once the belt 430 has been placed in position, the frame 188 may bereplaced and the apparatus operated substantially as described above.

Of course, the indexing means will no longer be used. This means thatthe liquid plastic will be laid down at an angle other than with respectto the longitudinal axis of the belt due to the simultaneous movement ofthe belt and the traversing movement of the nozzles. By adjusting therate of traverse and rate of movement of the belt, this angle can bemade to be minimal. In any case, its major effect would only benoticeable at the end of sheeting being produced which would normally becut off in any case.

Likewise, it is possible to employ stationary nozzles or even aplurality of horizontally disposed nozzles in the practice of thepresent invention. Adjustments in variable factors such as viscosity ofresin and the like, to accommodate alternative nozzle positioning caneasily be made without undue experimentation.

It can therefore be seen from the foregoing that the practice of thepresent invention contemplates providing sheeting containing orientedpearlescent material, which can be produced from resinous or polymericmaterials which set by evaporation of solvents alone or which set by anoxidative or polymerization process.

The plastic materials preferred in the invention disclosed herein,include a wide variety of unsaturated polyester resins. With suchmaterials it is necessary to use a promotor and/or accelerator, andcatalyst in the formulated resin mix to achieve the desired gelling orsetting of the sheeting. Preferably such materials may be selected fromorganic oxygen releasing compounds such as benzoyl peroxide, cumenehydroperoxide, cyclohexanone and methyl ethyl ketone peroxide. Likewise,the use of a promoter is preferred. Generally useful promotors areselected from metal soaps whose metal is oxidizable and capable ofchanging valence upward. Metal soaps such as cobalt naphthenate, cobaltoctoate, magnesium octoate, and zirconium tallate function well aspromotors. Selection of a promoter and the catalyst in the amountsuseful in this invention is a matter of choice to the artisan. No undueexperimentation is necessary to determine the optimum amounts ofselected materials for achieving a gel or setting point in the sheetingas described hereinbefore.

The term pearlescence as used herein is intended to encompass all of theclass of light-reflecting and light transmitting lamellae which havebeen widely used for the purpose of imparting integral white or coloredsheen to transparent or substantially transparent materials. Suchlamellae include the pearlescence obtained from fish scales, variousinorganic substitutes therefor, and metal bronze powders. The foregoingand other equivalent light-reflecting and light transmitting materialsmay be used in the practice of the present invention.

The following examples are typical of formulations used as describedherein to prepare plastic sheeting containing oriented pearlescence.

EXAMPLE 1 of New York 1.5 Styrene -10 Cobalt naphthenate (a 6% solution).75 Lupersol Delta-X, methyl ethyl ketone peroxide 1.0 A by weightsolution of Esso wax 4030 (a white parafiin wax) in styrene monomerStyrene monomer is added to the PE-205 polyester resin until the mixtureattained a viscosity of about 1200 cps. at 77 F. Wax is added and thethinned resin is then divided into two equal quantities. Thepearlescence and cobalt soap are added to one of the divided portionsand the organic peroxide catalyst is added to the other portion. Thecontents of the two containers are then mixed as described hereinbeforeusing equal flow rates from each container. As the mixed resin isexpelled directly onto the surface of trays 172, the rate of travel ofthe supporting belt or tray is adjusted to conform with the rate ofexhaust of the mixed resin so that the location of a predeterminedsetting or gel point can be controllably established downstream.Adjustment can also be made in the temperature environment for the castsheeting, a higher temperature accelerating the gelling or setting,thereby permitting faster travel of the web or tray, and a lowertemperature retarding the gelling or setting. The above formulation may,of course, contain greater or lesser amounts of cobalt naphthenate andorganic peroxide within wide limits depending upon the speed or distanceof travel desired for the formation of a nonflowable sheet. Further, theamount of styrene monomer added can be adjusted to produce a materialhaving a viscosity in the range of from about 400 to about 2500 cps. at77 F. and still obtain the desired results.

EXAMPLE 2 A typical formulation of a thermoplastic resin suitable foruse in preparing oriented pearlescent containing plastic sheeting can bemixed using the following representative amounts.

Nacromer ZPG-B, a nacreous or pearlescent pigment 1.5

Such a formulation is used in the manner described in Example 1 byadjusting the viscosity of the methyl methacrylate syrup to a value ofapproximately 1000 cps. at 77 F. by the addition of methyl methacrylatemonomer. The resulting liquid is then split into equal portions, as inExample 1. Dimethylaniline and Nacromer ZPG-B pearlescence are added toone portion and the thiophenol to the other. The discharging resin willgel in approximately 10 to 20 minutes, which time can be adjusted bychanging the temperature or the concentration of the thiophenol anddimethylaniline.

EXAMPLE 3 The following epoxy resin formulation is prepared:

Parts Epon 828, a bisphenol A-epichlorohydrin resin formulation sold byThe Shell Chemical Co. 80 Triethylene tetramine (hardener) 20 NacromerYGP, a pearlescent material manufactured by The Mearl Corporation 1.5

The ratio of hardener in the above formulation may be altered to controlgel time. Likewise changes in temperature will affect gel time, i.e., anincrease in temperature providing for a speedier gel.

The pearlescence is premixed with the entire quantity of Epon 828. Theentire portion of triethylene tetramine is kept in a separate container.Each portion is pumped to the mixing nozzle. The pump speeds are set tomaintain the predetermined formula ratio. The mixed resin from themixing nozzle is then applied in the manner described in the precedingexamples.

The viscosity of the epoxy resin system can be controlled by diluentswhich can be reactive or non-reactive. For example, the non-reactivediluents which can be used are xylene phthalate and dibutyl phthalate.Reactive diluents both monofunctional and difunctional may be used. Forexample, allyl, butyl, cresyl and phenol glycidyl ether, as well asdiglycidyl ether, vinyl cyclohexene and bis (2,3-epoxycyclopentyl)ethcr.

The hardener selected for use in the preceding formulation may beselected from among a large number of aliphatic amines which are capableof reacting with Bisphenol A-epichlorohydrim resins. For example,diethylene triamine, triethylene tetramine, diethylamino propylamine andamine terminated polyamides may generally be employed in stoichiometricquantities to produce the desired hardening function.

The present invention may be embodied in other specific forms withoutdeparting from the spirit or essential attributes thereof and,accordingly, reference should be made to the appended claim rather thanto the foregoing specification as indicating the scope of thisinvention.

We claim:

1. A method of continuously manufacturing oriented light reflectinglamellae-containing plastic sheeting comprising the steps of providing afirst source of settable fluid clear resin, providing a second source oflight reflecting lamellae-pigmented resin, continuously off-taking resinfrom said first and second sources in predetermined portions,continuously and mechanically intimately mixing said portions of resinsjust prior to applying the mixture of settable light reflectinglamellae-containing fluid resin to an area of a surface, and thenapplying the mixture of settable light reflecting lamellae-containingfluid resin to an area of a surface, said fluid resin being selectedfrom the group consisting of thermoplastic resins, thermosetting resinsand resin in solvent systems, continuously providing a fresh surface forthe application of the mixture by moving the surface area bearing themixture away from the point of application of said mixture, simultaneously imparting periodic motion to said moving surface solely alongan axis in the plane of said surface to orient the light reflectinglamellae until said fluid resin is rendered non-flowing while the uppersurface of said 13 14 fluid resin is exposed to the atmosphere, and thenremov- 3,232,819 2/ 1966 Satas 264216 X ing the oriented plastic resinfrom said surface. 3,303,245 2/1967 Trudeau 264-70 References CitedROBERT F. WHITE, Primary Examiner UNITED STATES PATENTS 5 A. M. SOKAL,Assistant Examiner 2,615,271 10/1952 Ulmer 264-70 X 2,921,346 1/1960Fischer 264-408 2,971,223 2/1961 Grunin 264-108X 264-73110?

